My mom was just recently "let go" from her place of employment, one of the reasons the owner cited was my mom "lied" to her about how she was keeping up on her bills/rent. The owner of my moms former employer and her landlord are friends, is there a law prohibiting an owner of a business discussing financial situations with a third party about the employees financial well being? Thank you..It just seems very fishy to me

Although such discussions are certainly unprofessional, not all unprofessional actions are illegal. And although her discharge may have been unfair (which, after all, is a subjective term), neither was it illegal.

She should file for unemployment immediately and start the job search. Honestly, I wouldn't want to be working for someone who would discuss my personal financial situation with a third party (although, in your mom's case, how the boss knew what her financial situation was could probably be gleaned only from mom).